Help! Car is running low revs and cutting out!

**Rachel** · 19-09-2006,12:06 AM

Hi

I'm new to this site. I've read quite a lot on here but thought I would post up my problem.

I have a W reg Volkswagen Golf 1.4 which I've had for 2 years.

When my car went in for it's MOT back in May I was told the engine management light came on while they were testing the emissions and advised that the Lambda sensor may need replacing and cleared the fault. They also said there was a hole in the exhaust so they replaced it and told me this could also be a reason the engine management light came on.

I have noticed over the last few months that the revs have been fluctuating between 500 and 700 and dropping as low as 400 when idle (the revs have always been at about 700) and occasionally my car will cut out while I am driving, usually as I am dropping down the gears. I have recently had a lambda sensor replaced as I guessed this was the problem (after doing a few searches on the internet and the garage telling me it may need replacing). This seemed to sort the problem for about a month. It has now starting cutting out again and the revs are dropping very low, it also doesn't run very smoothly, especially in 3rd gear. Does anyone have any idea what it could be? My car hasn't had a service for at least 16 months as my funds are limited. My car is going into the garage on Saturday to be hooked up to their machine to see if any faults will show and they suggested if I couldn't afford a service to at least have the oil and filter changed.

A few months ago I also noticed that my water was going down very quickly. I friend had a look and told me they thought the head gasket may need replacing. I took it to the garage to get it checked and they said it wasn't the head gasket. They couldn't find a fault apart from the pressure and suggested I change the cap which seems to have cured that problem. I am also having to top up my oil more often than usual.

I'm just trying to explain the problems I have encountered over the last few months just in case they are related.

Hope you can help.
Rachel.

**Rachel** · 24-09-2006,11:34 AM

My car went into the garage on Saturday and they couldn't find anything wrong with it!

They cleared out the breathing system as it was a bit clogged. Apparantly, all the short journeys aren't good for my car!

I'll see how it goes.

Rachel.

**Rachel** · 05-10-2006,10:41 PM

Well my car lasted just under 2 weeks before the engine management light came on again!!

This time there appeared to be nothing wrong. The car was running fine. Until I get it into the garage i guess I won't know what is wrong with it.

Any ideas???

Rachel.

**Rachel** · 09-10-2006,10:59 PM

Well here is another up date for those of you who may be interested.

My car went into the garage today to have the fault read. I have an intermitant problem with the Lambda sensor. As they have just replaced this they said that this wouldn't be the problem and that it is possibly the wiring to the lambda sensor. They checked it all and cleared the fault. But I have a feeling that I will be back to the garage in the very near future!!!

Rachel.

**onzarob** · 10-10-2006,09:05 AM

Nice to see you keep the thread updated it doesn't go unread.

Don't rule out the new sensor being faulty if the light comes back on, it has happend to me before.

Good luck

Rob

**Rachel** · 26-10-2006,11:03 PM

It's been 2 1/2 weeks since I posted my last message, and guess what? Yes, that bloody engine management light has come on again!!!

The car is going into the garage again on Wednesday and they are going to check the wiring.

I'm getting a bit fed up with it now and was hoping it would be sorted before the really cold weather comes are way. I am thinking of getting rid but can't really afford to do that! Anyone want to buy a dodgy Golf???

Rachel.

**Rachel** · 04-11-2006,12:19 AM

Another update.

The fault read that it was the lambda sensor again so the garage had an electrician to replace the pins. They cleared that fault and another one appeared. They replaced a sender unit but not to sure what that is but they did tell me that this can apparantly cause eratic revs??

Someone told me the other day that a friend of their's had a Golf, same year, model etc and they are having the same problems. They took the car to a mechanic that told them that he has seen this problems loads of times and told them that it was the air filter?? Do you think it is worth changing?

Lets see how long it is before the engine management light comes on again!

Rachel.

**adamss24** · 04-11-2006,12:53 AM

The ECU relies on a whole aray of sensors to make the engine run at optimum. To make the engine efficient the ecu is trying to stick to the stoikiometric rapport off 14.5: 1 of air to fuel to maximise efficiency. However it cannot keep that all the time so he has to make constant adjustments so thats why the lambda probe is there for. When an engine is hot and runs lean it produces more NOX(nitrogen oxides) and when it runs rich it returns poor economy but its easyer on the environment. When the lambda sensor fails he is pushing too much fuel that gets the catalist verry hot and thus the emission lights came on! Thats why its important to have a lambda probe within spec. Usually garages fit poor quality sensors and they deteriorate very quick.

**Rachel** · 08-11-2006,07:49 PM

5 days later the light is on again!

I not too sure what the problem is! Should I be losing all power when this happens?

If the fault reads the lambda sensor again is there anything else that's related to it that could be the problem. Is it coincidence that this all started after I had the exhaust replaced in may?

Rachel.

**adamss24** · 08-11-2006,08:45 PM

What is the mileage? Has the catalyst been replaced ? It could be that the catalyst may be plugged and not doing a propper job and lambda sensor knows it and turns the emission light on. Is the engine iddles steady at 900 rpm or is it going up and down?